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Excitons are quasiparticles made from the excited state of electrons and—according to research being carried out EPFL—have the potential to boost the energy efficiency of our everyday devices.

It’s a whole new way of thinking about electronics. Excitons—or quasiparticles formed when electrons absorb light—stand to revolutionize the building blocks of circuits. Scientists at EPFL have been studying their extraordinary properties in order to design more energy-efficient electronic systems, and have now found a way to better control excitons moving in semiconductors. Their findings appear today in Nature Nanotechnology.

Quasiparticles are temporary phenomena resulting from the interaction between two particles within solid matter. Excitons are created when an electron absorbs a photon and moves into a higher energy state, leaving behind a hole in its previous energy state (called a “valence band” in band theory). The electron and electron hole are bound together through attractive forces, and the two together form what is called an exciton. Once the electron falls back into the hole, it emits a photon and the exciton ceases to exist.

According to an update by MrBeast, Musk is now in the number one spot with the most trees. Second spot goes to MrBeast himself with only 100,002 trees.

Researchers have developed a new printer that produces digital 3D holograms with an unprecedented level of detail and realistic color. The new printer could be used to make high-resolution color recreations of objects or scenes for museum displays, architectural models, fine art or advertisements that do not require glasses or special viewing aids.

“Our 15-year research project aimed to build a hologram printer with all the advantages of previous technologies while eliminating known drawbacks such as expensive lasers, slow printing speed, limited field of view and unsaturated colors,” said research team leader Yves Gentet from Ultimate Holography in France. “We accomplished this by creating the CHIMERA printer, which uses low-cost commercial lasers and high-speed printing to produce holograms with high-quality color that spans a large dynamic range.”

In The Optical Society (OSA) journal Applied Optics, the researchers describe the new printer, which creates holograms with wide fields of view and full parallax on a special photographic material they designed. Full parallax holograms reconstruct an object so that it is viewable in all directions, in this case with a field of view spanning 120 degrees.

Light is the fastest way to distinguish right- and left-handed chiral molecules, which has important applications in chemistry and biology. However, ordinary light only weakly senses molecular handedness. Researchers from the Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy (MBI), the Israel Institute of Technology (Technion) and Technische Universitaet Berlin (TU Berlin) now report a method to generate and characterize synthetic chiral light, which identifies molecules’ handedness exceptionally distinctly. The results of their joint work have just appeared in Nature Photonics.

Like left and right hands, some molecules in nature have mirror twins. However, while these twin molecules may look similar, some of their properties can be very different. For instance, the handedness—or chirality—of molecules plays an essential role in chemistry, biology, and drug development. While one type of a molecule can cure a disease, its mirror twin—or enantiomer—may be toxic or even lethal.

It is extremely hard to tell opposite chiral molecules apart because they look identical and behave identically unless they interact with another chiral object. Light has long been used to detect chirality—oscillations of the electromagnetic field draw a chiral helix in space along the light propagation direction. Depending on whether the helix twirls clockwise or counterclockwise, the light wave is either right- or left-handed. However, the helix pitch, set by the light wavelength, is about 1000 times bigger than the size of a molecule. So the light helix is a gigantic circle compared to the tiny molecules, which hardly react to its chirality.

RUDN University mathematicians have proven the Hardy-Littlewood-Sobolev (HLS) inequalities for the class of generalized Riesz potentials. These results extend the scope of these potentials in mathematics and physics because the main tools for working with such potentials are based on HLS inequalities. New mathematical tools can greatly simplify calculations in quantum mechanics and other fields of physics. The results of the study are published in the journal Mathematical Notes.

Modern physics describes the world in terms of fields and their potentials—that is, the values of the field at each point. But the physical quantities that we can measure are forces and accelerations, that is, derivatives of the second-order of the potential of the corresponding field. The problem of reconstructing the field configuration with the available values of forces and accelerations observed in experiments is complex and not always analytically solvable. Differentiation operations in multidimensional space—operators are usually used to describe the correlation between the potential of the field and the forces. In particular, electromagnetic and gravitational interactions are described in the language of operators.

Since the potential of the field can be determined up to a constant value, for the convenience of calculations, the initial value of the potential is taken at some point in multidimensional space, or on the border of any spatial area. But in some cases, mathematical models of such fields lead to a singularity, that is, at some points the value of the field becomes infinite, and therefore loses its physical meaning.

The healthcare industry stores some of the sensitive personal information there can be about people: hackers know this and are looking to exploit what they view as an easy target.

Doctors have reported on the first attempts in the United States to use gene editing to help patients fight cancer.

The doctors say one form of gene editing appeared to be safe when tested in three patients. But it is not yet known what long-term effects the method will have on cancer treatment or patient survival rates.

A gene editing tool called CRISPR/Cas9 was used in the tests, which were recently reported in a medical study. The method was discovered in recent years as a way to change the genetic material that make up a person’s DNA.

A combined team of researchers from Lawrence Livermore National Laboratory in the U.S. and Atomic Weapons Establishment in the U.K. has found that rapidly compressing lead to planetary-core type pressures makes it stronger than steel. In their paper published in the journal Physical Review Letters, the group describes how they managed to compress the metal so strongly without melting it.

Defining strength in a material is difficult. Strength can refer to a material’s ability withstand bending or breaking under certain conditions. Making things even more complicated is that the strength of any given material can change under varying conditions—such as when heat or compression are applied. In this new effort, the researchers showed just how difficult it can be to nail down how strong a material is—in this case, lead.

Lead is not very strong. Pressing a fingernail against a car’s battery terminal is enough to create indentations, for example. But the researchers with this new effort report that the metal can be strengthened considerably by exerting extreme pressure.

Bacteriophages (phages) are viruses that specifically destroy bacteria. In the early 20th century, researchers experimented with phages as a potential method for treating bacterial infections. But then antibiotics emerged and phages fell out of favor. With the rise of antibiotic-resistant infections, however, researchers have renewed their interest in phage therapy. In limited cases, patients with life-threatening multidrug-resistant bacterial infections have been successfully treated with experimental phage therapy after all other alternatives were exhausted.

Researchers at University of California San Diego School of Medicine and their collaborators have now for the first time successfully applied phage therapy in mice for a condition that’s not considered a classic bacterial infection: alcoholic liver disease.

The study publishes November 13, 2019 in Nature.